Vibrating device



A. M. CURTIS I VIBRATING DEVICE Filed Feb.20, 1924 //7V6/7/0r.' Aus/en /V. Cur/i3 p My , stood by Patented Sept. 6, i927.

UNITED STATES P T- F C nusrnu M. scams. or EAST ORANGE, NEW JERSEY, nssrenon. r WESTERN nuns TRIO COMPANY, INCORPORATED, OF LNEW YORK, N.

YORK.

-Y., a conronarron or NEVT VIBRATING DEVICE.

Application filed February 20, 1924. Serial No. 694,106..

This invention relates to vibrating devices and particularly to a suspension for use on siphon recorders. In the standard type of siphon recorder the moving coil which is positioned in an air" gap in the magnetic field is supported by means of a biiilar suspension maintainedunder tension. Such an arrangement is satisfactory for low speed operation since the-necessary tension'of the suspension is notsuficient to cause any mechanical diiiiculties. iowever, when it IS desired to operate at high speeds it becomes necessary to increase the natural frequency of the coil system to'the required value by increasing the tension on the bifilar suspension. It is essential in an instrument designed forhigh speed recording that-the moving system be made as light as possible and it is therefore not capable of withstanding the increased tension and as a resultdiiiiculty is experienced due to the distortion of the coils, which gradually change in shape enough to rub against the magnetic core usually placed within the coil and also tend to develop short circuited turns.

It is an object of the present invention to suspend the moving coil of vibrating devices in such a manner that the 001i Wlll not be distorted by increase in the tension of the suspension. To accomplish this result the coil is preferably suspended by suitable wires which are substantially at right angles to the axis of rotation of the coil and which are rigidly secured to metal strips pro ecting from the short side of the coil.

The invention may be more clearly underdrawing in which Fig. 1 is a. front view of a siphon recorder suspension embodying the features of the invention and Fig. 2 is a bottom view of the suspension of Fig. 1.

Referring to the drawing the coil 3 carrying the siphon arm 4.- adapted to register with the recording tape 5 is provided at its ends with metal strips or end pieces 6-6 which are preferably of aluminum and are secured rigidly to the coil. The suspension wires 7 and 8 which are secured at their central portions to the endpieces are carried by supporting brackets 9 and 10 respectively. The front bracket 9, as shown more clearly in Fig. 1, is provided with a pair of right angled member or supports 11 and 12' and the rear bracket 10 is pro- Vided with similar supports 13 and 14. One

one end to a reference to the accompanying end of suspension wire 7 is secured to a fixed post 15 mounted in support 11 and the other end is secured to the freeend of the flexible spring 16 mounted on support 12. An adjusting screw 17 threaded into the support 12 has a head orv shoulder portion adapted to engage spring 16 to control ad justment of the tension of suspension wire 7 on rotation of the screw 17.], In a sin1- ilar manner suspension wire 8 is secured at fixed post 19 mounted in support 13, while the other-end is secured in flexible spring 2 mounted on support it and the tension of the means of adjusting screw 21. V

In order to permit accurate positioning. of thecoil 3' in the magnetic field existing between pole-pieces22-22,tl1e brackets 9 and 10 are made adjustable in a direction parallel to the axis of the pole-pieces. Adjustment of the front bracket 9 is obtained by means of the adjusting rod 23 and guiding rod 24 cooperating with the fixed supports 25 and 26. One end of rod 23 is dimensioned to pass freely through suitable openings in bracket 9 and support 26, and the other end is provided, with a threaded por-" tion adapted to engage corresponding threads in the support 25. Thrust collars 27-27 are keyed to rod 23 as shown to control the movement of bracket 9, and a knurled knob 30 is also keyed to the rod to facilitate operation. The guiding rod 24 is in the drawing. In order to reduce the re-' luctance of. the air ap between pole-pieces 2222, a center 6 core member 32v is provided for coil 3, being dimensioned so to permit free movement of the coil, and is rigidly mounted equi-distant between the polepieces.

It will be noted from the above descriprestoring force is provided to o pose rota tion of the coil, but the tension of the suspension "wires is'not transmitted through the sides of the coil, as in previous designs,

,and thereforev cannot subject the'coil to any distorting strain. The horizontal adjustment moreover, offers a further advantage 7 tion that in this device an adjustable elastic in that it permits an unobstruced view of the tape upon which the signals are being written by the siphon arm attached to the coil.

5 Although the suspension wires are preferably perpendicular to the axis of rotation of the coil it is obvious that their direction may be changed somewhat without causing distortion of the coil so. long as When under tension the component oi? the force acting in a direction parallel to the axis of the coil is small as compared with the component acting in a direction perpendicular to the axis of the coil.

WVhat is claimed is:

1. In a--vibr'ating device, a coilrotatable about an axiswithin-v itself and elastic means for supporting said coil withoutexerting strains thereupon in; the direction of the axis of rotation.

2. In a vibrating. device, a member rotatable about an axis within itself, and a plurality of suspension wires rigidly secured thereto, said suspension wires being so. positioned that whenunder tension their component in a direction perpenlicular to the axis of rotation of the coil is greater than their component in. a direction parallel to the axis of the coil.

3; Ina vibrating device,

a member rotat-v able about an axis Within itself, and a plurality of suspension wires rigidly secured thereto, said suspension wires being substantially perpendicular to the axis of rotation of the rotatable member.

4;. In a vibrating device, a rotatable member and a pair of suspension Wires rigidly secured at their central portions to said member, said wires being substantially perpendicular to the axis of rotation of the rotatable member.

5. In a vibrating device, a rotatable coil having its axis of rotation in a horizontal plane, and aplurality o't' horizontal suspension wires perpendicular to the axis of rotation, of the coil rigidly secured at their central portions to said coil.

('3. In a vibrating device, a coil rotatable about an axis within itself, a magnetic cir cuit therefor including a pair of pole-pieces, means for adjusting the position of the coil with respect to said pole-pieces, elastic means for both supporting and restoring said coil withoutexerting longitudinal strains thereupon, and means for varying the tension oi? said restoring means.

In witness whereof, I-hereunto subscribe my name this l2th day oi. February A. 1).,

AUSTEN M. CURTIS. 

